This invention relates generally to separable fasteners of the type which joins two members simply by pressing the two members together and separates them by pulling apart, and more particularly to separable fasteners having a similar construction for both members. Press-on and pull-off separable fasteners of the prior art generally are of the type where one member has a surface including a large number of closely spaced fastening elements of one type which engage in a face-to-face relationship with another type of closely spaced complementary fastening elements on the other member. On the other hand, zipper-type fasteners comprise two members which are engaged in a side-to-side relationship.
A well known cloth-type press-on/split-off fastener uses a first cloth member having flexible hooks mounted on one face. The other cloth member has a large number of loops mounted on the face. The two members fasten together when pressed face-to-face with the hooks engaging the loops. The two members are separated by pulling the members apart such that the bond between the loops and hooks is broken. The members are reusable; the connection can be made and broken many times. However, a connection made between two portions of the same surface, for example, by looping a tape to form a belt, does not form a good bond when loops mate with loops or hooks engage hooks.
Plastic separable fasteners have been developed wherein a tape includes corrugated resilient strips extending longitudinally along the tape. The corrugations of adjacent strips are staggered, being formed by deformation and piercing of a single flat plastic sheet. Connection of members is made by pressing two identical surfaces face-to-face such that the staggered strips of one tape interleave with the staggered strips of the mating tape. Thus, a tape can be looped around and joined to its ends, for example, to form a strap or belt without the need for two different surface configurations on the mating parts.
However, the alternating strips of corrugated plastic material having a disadvantage, namely, that little material is left between the staggered adjacent strips to bond them together laterally. Therefore, only slight effort is required to cause the tape to tear longitudinally at an intersection between corrugated adjacent strips. Further, when the tape is cut transversely across the corrugations, a frayed edge is left resulting from broken corrugation loops. Additionally, when folded transversely, the tape readily takes a permanent set and reusability is diminished.
What is needed is a separable fastener of the press-on/pull-off type which forms a strong connection, joins to an identically formed member, is tear resistant, reuseable and economical to produce.